The strong claim that "interrupt_main is now equivalent to the user having hit control-C" is the reason I suggested broadcasting CTRL_C_EVENT via GenerateConsoleCtrlEvent. That operation isn't buggy on its own to my knowledge. There is a glitch due to the CRT. If a non-console process calls AllocConsole or AttachConsole, its list of registered handlers gets reset to the default handler that calls ExitProcess, and the CRT provides no way to set its handler again. 

I mentioned the possibility of calling CancelSynchronousIo in order to cancel a console read like Ctrl+C does (but clunkier) -- again, because of the equivalence claim. ERROR_OPERATION_ABORTED would need to be handled like EINTR on Unix. This would entail small changes to a lot of code, so it does need a separate issue if there's any support for this idea.